2014 September 7, Natalie Angier, “The Moon comes around again [print version: Revisiting a moon that still has secrets to reveal: Supermoon revives interest in its violent origins and hidden face, International New York Times, 10 September 2014, p. 8]”, in The New York Times‎[1]:

Unlike most moons of the solar system, ours has the heft, the gravitational gravitas, to pull itself into a sphere.